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Audio file format issue in objective c


I have written an audio WAV (have recorded my voice) file using AVAudioRecorder. The final file format is a WAV file. File was successfully saved and I can hear my voice. I want to send this file to a back End server (web-service). But my server accepting only data and FMT information in WAV . It is not accepting my wav file because of my wav file infromation with FLLR, data, FMT. I have checked my WAV file information in Riffpad tool. It's showing FLLR, data, FMT. But I want only data and fmt. Because my server side accepts only data and FMT. So please advice how to remove FLLR in my wav file in programmatically?

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My source code for the record:

  NSError *error;

    // Recording settings
    NSMutableDictionary *settings = [NSMutableDictionary dictionary];
    [settings setValue: [NSNumber numberWithInt:kAudioFormatLinearPCM] forKey:AVFormatIDKey];
    [settings setValue: [NSNumber numberWithFloat:22050] forKey:AVSampleRateKey];
    [settings setValue: [NSNumber numberWithInt: 1] forKey:AVNumberOfChannelsKey]; // mono
    [settings setValue: [NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
    [settings setValue: [NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey];
    //[settings setValue: [NSNumber numberWithInt:16] forKey:AudioSampleType];




    // File URL
    NSURL *url = [NSURL fileURLWithPath:FILEPATH];

    //NSLog(@"Url file path ::: %@",url);

    // Create recorder
    recorder = [[AVAudioRecorder alloc] initWithURL:url settings:settings error:&error];
    if (!recorder)
    {
//        NSLog(@"Error establishing recorder: %@", error.localizedFailureReason);
        return;
    }

Solution

  • Thank God and your support friends. Yes finally i solved my issues. I don't know the way is correct. But my issues is solved. I recorded voice using above code and save my audio .Then again i will export the audio using the following code. I got this code from https://developer.ibm.com/answers/questions/180732/seems-watson-text-to-speech-service-returns-a-wav.html

    -(NSData*) stripAndAddWavHeader:(NSData*) wav {
        unsigned long wavDataSize = [wav length] - 44;
    
        NSData *WaveFile= [NSMutableData dataWithData:[wav subdataWithRange:NSMakeRange(44, wavDataSize)]];
    
        NSMutableData *newWavData;
        newWavData = [self addWavHeader:WaveFile];
    
        return newWavData;
       }
    
    
     - (NSMutableData *)addWavHeader:(NSData *)wavNoheader {
    
           int headerSize = 44;
           long totalAudioLen = [wavNoheader length];
           long totalDataLen = [wavNoheader length] + headerSize-8;
           long longSampleRate = 22050.0;
           int channels = 1;
           long byteRate = 8 * 44100.0 * channels/8;
    
    
    
         Byte *header = (Byte*)malloc(44);
         header[0] = 'R';  // RIFF/WAVE header
         header[1] = 'I';
         header[2] = 'F';
         header[3] = 'F';
         header[4] = (Byte) (totalDataLen & 0xff);
         header[5] = (Byte) ((totalDataLen >> 8) & 0xff);
         header[6] = (Byte) ((totalDataLen >> 16) & 0xff);
         header[7] = (Byte) ((totalDataLen >> 24) & 0xff);
         header[8] = 'W';
         header[9] = 'A';
         header[10] = 'V';
         header[11] = 'E';
         header[12] = 'f';  // 'fmt ' chunk
         header[13] = 'm';
         header[14] = 't';
         header[15] = ' ';
         header[16] = 16;  // 4 bytes: size of 'fmt ' chunk
         header[17] = 0;
         header[18] = 0;
         header[19] = 0;
         header[20] = 1;  // format = 1
         header[21] = 0;
         header[22] = (Byte) channels;
         header[23] = 0;
         header[24] = (Byte) (longSampleRate & 0xff);
         header[25] = (Byte) ((longSampleRate >> 8) & 0xff);
         header[26] = (Byte) ((longSampleRate >> 16) & 0xff);
         header[27] = (Byte) ((longSampleRate >> 24) & 0xff);
         header[28] = (Byte) (byteRate & 0xff);
         header[29] = (Byte) ((byteRate >> 8) & 0xff);
         header[30] = (Byte) ((byteRate >> 16) & 0xff);
         header[31] = (Byte) ((byteRate >> 24) & 0xff);
         header[32] = (Byte) (2 * 8 / 8);  // block align
         header[33] = 0;
         header[34] = 16;  // bits per sample
         header[35] = 0;
         header[36] = 'd';
         header[37] = 'a';
         header[38] = 't';
         header[39] = 'a';
         header[40] = (Byte) (totalAudioLen & 0xff);
         header[41] = (Byte) ((totalAudioLen >> 8) & 0xff);
         header[42] = (Byte) ((totalAudioLen >> 16) & 0xff);
         header[43] = (Byte) ((totalAudioLen >> 24) & 0xff);
    
         NSMutableData *newWavData = [NSMutableData dataWithBytes:header length:44];
         [newWavData appendBytes:[wavNoheader bytes] length:[wavNoheader length]];
         return newWavData;
     }